Manufacture of oxids of nitrogen.



CARL BOSCH, ALWIN MITTASCH, AND CHBISTOPH BECK, F LUDWIGSHAFEN-ON THE-RHINE, GERMANY, ASSIGNORS T0 BADISCHE ANILIN & SUDA FABRIK, 0F LUIDWIGSHAFEN-ON-THE-RHINE, GERMANY, A CORPORATION OF GERMANY.

l MANUFACTURE OF OXIDS 0F NITROGEN.

memos.

No Drawing. v

To all whom it may concern: v

Be it known that We, CARL Boson, ALWIN l /IIrTAsoH, and CHRISTOPH BECK, citizens of the German Empire, residing at Ludwigsl1afen-on-the-Rhine, Germany, have invented new and useful Improvements in the Manufacture of Oxids of Nitrogen, of which the following is a specification.

We have found that the catalytic oxidation of ammonia with the formation of oxids of nitrogen is effected in avery advantageous manner by passing a mixture of ammonia and oxygen-containing gas, such as air or oxygen, over a hot catalytic agent containing at least one oxid of a metal of the iron group (in particular an oxid of iron, 'manganese, chromium or uranium) and at least one oxid of a .rare earth metal, and that very favorable results are obtained, if the t) catalytic agents contain, besides said con- I stituents a compound of bismuth, for example an oxid of bismuth. In addition to the above compounds, the

catalytic agent may contain other substances,'

5 for instance, binding agents, such as calcium oxid, magnesia or alumina, but it is. preferred to avoid the presence of certain non-metallic elements and metalloids and compounds thereof, such as sulfuric acid,

ao'phosphoric acid, boric acid and silica, or at any rate larger quantities. thereof.

The production of the catalytic mixtures can advantageously be carried out by precipitating or calcining mixtures of salts of the components and then forming into suitably shaped pieces or lumps; and we prefer to employ the said catalytic mixtures in a layer, or layers, of small lumps. The pro portions of the ingredients can be varied 40 considerably. v v,

The following example will serve to further illustrate the nature of our invention which, however, is not confined to the exam ple. The parts are by "weight.

Example: Dissolve 15 parts of ferric ni trate and 1 part of lanthanum nitrate. in

water and precipitate the hot solution with ammonia. Filter, wash Well, form into Specification of Letters Patent.

muth.

Patented nee, as, rare.

Application filed February 25, 1915. Serial No. 10,625.

about 600 (1, then pass a mixture of ammoniaand air through the mass at about 750 C. lnithis example instead of lanthanum nitrate, other rare earth metals, or mix tures thereof, in particularthe cerite and the yttria earths, can be added and further salts or oxids of another metal of the iron group or of two, or more, of those metals can be employed. Thus, for instance, catalytic mixtures containing ferric oxid and yttrium oxid, or manganese oxid and cerium oxid, or manganese oxid, ferric oxid and didymium oxid may be used. Tn all cases a compound of bismuth may also be present.

Now What we claim is 1. The manufactureof oxids of nitrogen by passing a mixture of ammonia and an oxygen-containing gas over a heated catalytic agent containing at least one oxid of a metal of the iron group and at least one oxid of a rare earth metal.

2. The manufacture of oxids of nitrogen 7 by passing a mixture of ammonia and an oxygen-containing gas over a heated catalytic agent containing at least one 01nd of a metal of the iron group and at least one oxid of a rare earth metal and an oxid of bismuth.

4. The manufacture of oxids of nitrogen by passing a mixture of ammonia and an oxygencontaining gas through a layer of separate lumps of a heated catalyticagent containing atleast one oxidof a metal of the iron group. and at least one oxid of a a rare earth metal.

p 5. The manufacture of oxide of nitrogen v P "by passinga mixture of ammonia and an oxygen containing gas through a layer of separate lumps of a heated catalytic agent containing at least one oxid' of a metal of f rare earth metal and a compound oft.bis-' the iron group and at least one oxid' ofa 6. The manufacture of oxids of nitrogen by passing a mixture of ammonia and an ox \'gonconta1ning gas through a layer of separate lumps of a heated catalytic agent containing at least one oxicl of a metal of the iron group and at least one oxid of a rare earth metal and an oxid of bismuth.

In testimony whereof we have hereunto set our hands in the presence of two subscribing witnesses.

CARL BOSCH.

ALWIN MITTASCH.

CHRISTOPH BECK.

Witnesses ARTHUR DENONVILLE, JOIIANNES ACIIAIEL. 

